Evidence map›Paper›PMID 40327895›Full record

ArticleTree physiology2025

Repeated nitrogen fertilization enhances Scots pine growth and carbon uptake without persistent long-term effects in boreal forests.

Anni Palvi, Eduardo Martínez-García, Paul Szejner, Katja T Rinne-Garmston, Giles H F Young, Elina Sahlstedt, Raisa Mäkipää, Aleksi Lehtonen

Abstract read
In one paragraph

Article in Tree physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Anni PalviNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
Eduardo Martínez-GarcíaNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
Paul SzejnerNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
Katja T Rinne-GarmstonNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
Giles H F YoungNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
Elina SahlstedtNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
Raisa MäkipääNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.
Aleksi LehtonenNatural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland.

Funding

European Research Council 755865European Union's Horizon 2020 101000289Finnish Ministry of Agriculture and Forestry VN/10860/2023-MMM-2
6 · The paper itself

Abstract

Nitrogen (N) fertilization is known to enhance tree biomass production and carbon (C) assimilation in N-limited boreal forests. Yet, the long-term effects of repeated N applications remain limited. Here, we evaluate the impact of repeated N fertilization at 10-year intervals over six decades on a nutrient-poor Scots pine (Pinus sylvestris L.) forest in Central Finland. The analysis encompassed both short-term (single N-addition) and long-term (multi-decadal repeated N-additions) responses of basal area increment (BAI) and carbon isotope composition in tree rings (δ13C) from fertilized and control plots from 1960 to 2022. Furthermore, needle mass and chemistry were investigated, and stand-level nitrogen-use efficiency (NUE, amount of stem volume or tree C increased per unit mass of N added) estimated. We found that a single N-addition had a positive short-term effect on the tree ring δ13C during the first 2 years after fertilization. This suggests a combined effect on increase in photosynthetic activity and stomatal conductance, likely driven by greater needle mass and higher N content. Basal area increment showed a delayed but rapid increase, attributable to enhanced needle mass from improved photosynthesis, reaching its peak 2 years after fertilization, and then persisting for a period of 4-7 years. However, by the end of each decadal fertilization cycle, BAI and δ13C values in N treatment reached those of control, demonstrating no lasting site carry-over effects. The mean decadal NUE for the tree stem volume was 0.16 m3 per kg N added, indicating a significant degree of N retention in the forest ecosystem. After six decades, the cumulative impact of repeated fertilization led to a 47% increase in BAI in fertilized plots compared with controls, demonstrating the efficacy of accumulated short-term growth enhancements. Our findings highlight the potential of repeated N fertilization as an effective forest management practice to support the bioeconomy and mitigate climate change in nutrient-poor boreal forests.

Indexed as

CarbonFertilizersNitrogenPinus sylvestrisCarbon IsotopesFinlandForestsPhotosynthesisTaigaTreesCarbonCarbon IsotopesFertilizersNitrogenclimate changeforest managementforest productivityintrinsic water-use efficiencynutrient limitationwood production

Identifiers

PMID40327895
PMCPMC12166546

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.